Search Results for: how to put table in a result set

Why base64-output=DECODE-ROWS does not print row events in MySQL binary logs

Lately I saw many cases when users specified option --base64-output=DECODE-ROWS  to print out a statement representation of row events in MySQL binary logs just to get nothing. Reason for this is obvious: option --base64-output=DECODE-ROWS  does not convert row events into its string representation, this is job of option --verbose . But why users mix these […]

Google Compute Engine adds Percona XtraDB Cluster to click-to-deploy process

I’m happy to announce that Google has added Click-to-deploy functionality for Percona XtraDB Cluster (PXC) on Google Cloud Compute nodes. This gives you the ability to rapidly spin up a cluster for experimentation, performance testing, or even production use on Google Compute Engine virtual machines. What is Percona XtraDB Cluster? Percona XtraDB Cluster is a […]

Timezone and pt-table-checksum

I recently worked through an issue with a client trying to detect data drift across some servers that were located in different timezones.  Unfortunately, several of the tables had timestamp fields and were set to a default value of CURRENT_TIMESTAMP.  From the manual, here is how MySQL handles timezone locality with timestamp fields: Values for TIMESTAMP columns are […]

Distributed Set Processing with Shard-Query

Can Shard-Query scale to 20 nodes? Peter asked this question in comments to to my previous Shard-Query benchmark. Actually he asked if it could scale to 50, but testing 20 was all I could due to to EC2 and time limits. I think the results at 20 nodes are very useful to understand the performance: […]

A workaround for the performance problems of TEMPTABLE views

MySQL supports two different algorithms for views: the MERGE algorithm and the TEMPTABLE algorithm. These two algorithms differ greatly. A view which uses the MERGE algorithm can merge filter conditions into the view query itself. This has significant performance advantages over TEMPTABLE views. A view which uses the TEMPTABLE algorithm will have to compute the […]

RAID throughput on FusionIO

Along with maximal possible fsync/sec it is interesting how different software RAID modes affects throughput on FusionIO cards. In short conclusion, RAID10 modes really disappoint me, the detailed numbers to follow. To get numbers I run

test with 16KB page size, random read and writes, 1 and 16 threads, O_DIRECT mode. FusionIO cards are […]

Maximal write througput in MySQL

I recently was asked what maximal amount transactions per second we can get using MySQL and XtraDB / InnoDB storage engine if we have high-end server. Good questions, though not easy to answer, as it depends on: – durability setting ( innodb_flush_log_at_trx_commit = 0 or 1 ) ? – do we use binary logs ( […]